Herbivory and Plant-Pathogen Interations. Chapter 11. Herbivory – the consumption of all or part of a living plant. 4 types of Herbivores Granivores : consume seeds or grains, killing the individual within. Grazers : eat grasses and other low-growing plants.
Plant populations are limited by such abiotic factors as water, light, and soil nutrients.
Therefore, plant populations are not limitid by biotic factors such as herbivores.
Figure 11.3 a
Figure 11.3 b
Figure 11.4 a
Figure 11.4 b
Biological control- use of herbivores by humans to control populations of undesirable plant species.
Cactoblastiscactorum in Argentina
Fruit infected with a fungus
Flowers of Saponaria ocymoides
with anthers infected with a smut
Chemical defenses – Phytoalexins (may see localized and even systemic resistance)
Physical defenses - Phloem plugging
Ability to cause a diseases in a host – dependent on resistance genes and avirulence genes
The ability of and infectious agent to produce disease and a measure of the degree of damage inflicted
The ability of a plant to maintain its fitness when infected with a pathogen